(Red text is an electronic watermark that is not physically part of the photo for sale).
By the start of Operation Barbarossa, the German invasion of the Soviet Union, in 1941 the 21 panzer divisions had undergone further reorganisation to now consist of one tank regiment (of two or three battalions) and two motorised regiments (of two battalions each). Until the winter of 1941/42 supporting troops organic to these divisions consisted of a motorised artillery regiment (of one heavy and two light battalions), and one each reconnaissance, motorcycle, anti-tank, pioneer, field replacement, and communications battalions. The number of tanks in the 1941 style divisions was comparatively small, but all other units in these formations were fully motorised (trucks, half-tracks, specialized combat vehicles) to match the speed of the tanks.
During the winter 1941/42 another reorganisation of these divisions became necessary, each tank regiment now composed of one to three battalions depending on location (generally three for Army Group South, one for Army Group Centre, other commands usually two battalions). Throughout 1942 the reconnaissance battalions were merged into the motorcycle battalions.